FIG. 1 is a partially assembled view which illustrates a conventional swing assembly 1 for children disclosed in U.S. Pat. No. 6,872,146 B1. The rotor of a motor 10 in the FIG. 1 is connected to a worm 11 which meshes with a worm gear 12. One end of a sliding rod 13 is pivotally connected to one side face of the worm gear 12 and another end of the sliding rod 13 is pivotally connected to a pivoting piece 14. The pivoting piece 14 is also used to secure one end of a spring 15.
When the motor 10 rotates, its movement is sequentially transmitted through the worm 11, the worm gear 12, the sliding rod 13 and the pivoting piece 14 to the spring 15. Because another end of the spring 15 contacts the a stopper 16, the restoration force resulting from deformation of the spring 15 is transmitted through the pivoting piece 14 and the sliding rod 13 to the worm gear 12 such that a swing rod 17 swings at a predetermined angle like a pendulum. Hence, a sitting device connected to the swing rod 17 at lower end thereof can be swung relative to a skeleton 18.
However, when the weight of the child in the sitting device exceeds the rated load of the motor 10, the sitting device is blocked by miscellaneous articles from being swung, or another child outside the sitting device intentionally holds the sitting device, the sitting device looks stationary but the motor 10 is still electrically active. Therefore, the motor 10 will be damaged due to overloaded current.
Besides, if outage happens or electric power is suddenly cut off when the sitting device is swung to a place other than the lowest position, the sitting device will fixedly stop at a relatively higher position immediately. This situation is similar to emergently braking a car, which causes the child in the sitting device to tilt forward or backward unexpectedly. In addition, the orientation of sitting device at that position makes the child therein uncomfortable
Furthermore, the conventional swing assembly 1 is not equipped with a shielding device so that the conventional swing assembly 1 is not suitable for being used under the sun.